Laptop battery runtime reduced in Hardy compared to Gutsy

Bug #219648 reported by Uphaar Agrawalla on 2008-04-19
Affects Status Importance Assigned to Milestone
linux (Ubuntu)

Bug Description

Binary package hint: gnome-power-manager

I'm running an up-to-date Hardy (AMD64).

Under Windows XP, my laptop battery provides a full 3 hour backup.
Under Ubuntu Gutsy, the backup time has always been 2 hours 30 mins.

With Hardy supporting "dynticks" which is supposed to bring better power management to 64-bit machines, I thought that the backup time would go up. However, ever since I upgraded to Hardy, the battery only provides 2 hours backup! Thats a big drop.

It is not just the reporting time, as I know there are bugs open about that being displayed incorrectly. But the laptop actually powers off after 2 hours.

This looks like a regression at the very least.

It happens the same to me, but I'm running a 32bit laptop. XP lives almost 5.5 hours, Gutsy 4.25 and Hardy... 3.25!! I think it has something to do with the wi-fi chip (bcm43) because when I turn it off the energy consumption drops down, but still short battery life.

This is something I hoped it was improved in Hardy... I'll have to wait...

Thanks anyway.

I've noticed that when I boot with the Gutsy kernel battery life is 26% longer, and change time it's reduced a lot!! Hardy kernel must have some bug with power management.

Pedro Villavicencio (pedro) wrote :

Thanks for the bug report. This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find.

Changed in gnome-power-manager:
status: New → Invalid
Uphaar Agrawalla (uphaar) wrote :

The other bug is about Fiesty -> Gutsy, whereas this bug is about Gutsy -> Hardy. Besides, the other bug has been marked as invalid saying it's not assigned to the right package. If the package is not right, please re-assign to the right one or suggest someone do so instead of simply marking it invalid.

I'm removing the duplicate status. It is still marked invalid against g-p-m but open against linux.

Uphaar Agrawalla (uphaar) wrote :

Just to add, this is a crucial bug for a lot of Acer laptop users as they're facing this bug. These laptops are becoming quite common due to their low cost.

Buttay (cyril-buttay) wrote :

Same problem here on a Dell latitude D630, battery life used to be 3h on Gutsy, and is 2h on Hardy!

Furthermore, the output of the gnome battery widget is not consistent with the output of powertop:

3.6 hours estimated with powertop, 2h with the gnome energy manager

GeraldShastri (geraldshastri) wrote :

I am running Hardy on an Inspiron 6400 and I am facing the same problem. Earlier with Gutsy the power manager used to show me around 3 hours of battery backup now it has dropped to 1 hour 40 minutes.

There hasn't been any recent activity in this bug report and we were wondering if this is still an issue? The Ubuntu kernel team is actively working on the upcoming Intrepid Ibex 8.10 release. If you could please test the latest Alpha release for Intrepid it would be much appreciated - . Please let us know your results. If the issue still exists, please also provide the appropriate debugging information as outlined at . Thanks in advance.

Changed in linux:
status: New → Incomplete

The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:

1) If you are comfortable installing packages on your own, the linux-image-2.6.27-* package is currently available for you to install and test.


2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch for Alpha5 to be announced. You should then be able to test via a LiveCD.

Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.

Uphaar Agrawalla (uphaar) wrote :

Leann: Yes, the issue is still present in Hardy. Why has this been marked Incomplete? If you need any information please let me know and I'll try my best to get it for you. I'm changing the status to Confirmed as several people have confirmed this issue.

Regarding the 2.6.27 kernel, as I mentioned in another bug report I am willing to test it if it is available for Hardy and not dangerous to use. It is not possible to upgrade to Intrepid Alpha as this is my only laptop.

Changed in linux:
status: Incomplete → Confirmed

Uphaar Agrawalla, thank you for reporting this and helping make Ubuntu better. Hardy desktop reached EOL on May 12, 2011.
Please see this document for currently supported Ubuntu releases:

We were wondering if this is still an issue on a supported release? If so, can you try with the latest development release of Ubuntu? ISO CD images are available from .

If it remains an issue, could you run the following command in a supported release from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux <replace-with-bug-number>

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

no longer affects: gnome-power-manager (Ubuntu)
tags: added: hardy needs-upstream-testing regression-release
Changed in linux (Ubuntu):
status: Confirmed → Incomplete
Launchpad Janitor (janitor) wrote :

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Changed in linux (Ubuntu):
status: Incomplete → Expired
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